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Raymond J1

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Everything posted by Raymond J1

  1. Why to close complete the cowl flaps in cruise ? In fact, the complete close cowl flap is for the descent flight... No ? Best new year for all.
  2. 80% of accidents are caused by human failure. To replace the human with something else is to modify the occurrences on these 80% of human origin... But the machine is also fallible, so this does not balance the totality of human failures. In an automatic machine, it is therefore necessary to resolve to accept a failure rate of about 20 - 25%, which will not necessarily lead to an accident.
  3. If my words seemed disrespectful to you, please accept my sincere apologies because I do not intend to leave this impression or even harm. My job is precision mechanics, with several years in aircraft construction, aircraft restoration is also my passion. I have a reputation for being precise and picky, a requirement of my profession which is also my nature. So sometimes this translates in my writings by the use of dedicated terms and the desire to explain what the business rules require, but also the corollary, that is, what tinkered or technically unfounded operations can generate. I am also a private pilot, so I understand the expectations of the pilot who owns an aircraft. Don't blame others for not being constructive if you don't even give a constructive testimony. If you don't understand my words, because of my imperfect translations or my poor command of the language, ask, I can rephrase without problem.
  4. I liked for a few seconds the nickname of French AI... Because the US AI says that the Mooney M20 is a high-wing aircraft...
  5. I'll take an example... More simply... You are in the situation of a user who has a very developed engine monitoring, you are equipped to follow the constants of its operation. You are a perfectionist and have all this : -Pressures (oil, Map, fuel,...), -Flow rates (oil, air,...), -Temperatures (CHT, OAT, EGT, oil,...), -Speeds (engine/propeller, tubo...), As it is much too expensive, you do not have the vibratory tracking (acoustic) and you preferred a very comfortable ANR headset to hear the radio well... Question : Do you know the influence on the engine parameters that you follow from an exhaust valve that gets stuck or flu in its guide? Do you know what happens when an oil injector under the piston is clogged and no longer sprinkles oil on the said piston bottom to cool it? The two phenomena mentioned above are some of the beginnings of a malfunction of the engine, do you know how to tell if these are effects or if these are the causes of the malfunction? In truth, they are both effects, but most technicians will tell you that they are the cause of something... They do not cause the engine to stop, at worst we notice the destruction of the rocker rods, a loss of power, at best just a buckling of the rocker rods and sometimes a return to normal operation as soon as the oil temperature has dropped again (for example after a sustained climb to altitude and then the passage to cruising level). Because yes, when this happens, parameters vary, first the speed and the vibrations (the acoustics change) and then the temperatures. When a valve erases in its guide, it is after the temperature of the oil increases and again after the CHT changes, what changes first is the speed, consequence of a poor efficiency of the cylinder concerned... So the effects are noticed afterwards... Unless you mistakenly consider that the effects would be causes. But you don't monitor the noise in addition to having a radio headset on your ears and the speed is regulated by the mechanism of your propeller at constant speed... So you will not see and you will not hear the first effects. If you had monitored the acoustics or the vibration of the engine, then you would have had the information of what is happening at the moment when this happens... But it's out of budget. And so on the contrary, when the monitored deviations are noticed, who knows how to build among the user pilots a tree of the causes of failures and above all, at what too late moment are the damages noticed? What I am writing to you has been known for a long time, and the onboard monitoring on board has not revealed the thing, it has been known since the late 30s and discovered with the use by engine manufacturers of complex installations for monitoring engine parameters. It is these errors of considerations between causes and effects and also the late observation of damage that led to preventive maintenance interventions towards the end of the 1940s, i.e. the creation of time stops between TBO to assess and note (instead of imagining) the partial state of a mechanism, what we call in mechanics the reference states. The reference states are clearance or adjustment values that allow the proper operation of the engine, if they change or if they are modified, then the operation of the engine and the performance are impacted. Are not considered as reference state which does not impact the operation of the engine when the state changes. For example, the spacing of the spark plug filaments is a reference state... The degree of timing of the ignition advance is another, the same applies to the valve guide clearances, the rocker arm clearances,... The oil pressure set with the setting of the oil pressure regulator is a reference state... Do not confuse reference state and performance parameter... The engine speed, for example, it is not a reference state, it is just a parameter to check that allows you to see that the engine performance is obtained. So in mechanics, during a certain period of the history, the intelectual construction of a serious maintenance is the preventive method, it consists in ascertaining by factual readings the reference states of the mechanism and possibly carrying out corrective measures to find these states when they are in deviation. The BS of a manufacturer like Lycoming who suggests that you measure the clearance at the valve guides every 400 hours fits into this philosophy. The periodicity of 400 hours is also defined as sufficient... So for your 4 cylinder O 360, every 100 hours you know what you have to do: Control the clearance with the guides of a cylinder. The magnetos at 200 hours and alternately... The candles at 50 o'clock... Preventive maintenance has one cause of failure: The incorrect execution of simple operations with partial disassembly. Because the consequence of a bad reassembly of the partially deposited thing is sometimes worse than the degradation of the reference state that it was desired to correct. And it is this observation that towards the end of the 70s led to monitoring certain reference states, or the effects they generate, in order to avoid serious failures following minor maintenance intervention. This is the creation of "predictive" maintenance, that is, the one that bases the service time between repairs (and not TBO) on the basis of performance records in service. This is another topic, but the procedure of "fluid management" is for example one of the tools of predictive maintenance... On the contrary, you cannot pretend to do predictive maintenance with an oil change at 50 h which is a preventive maintenance solution. Well, it's the same reasoning with someone who explains to you to do monitoring and change his candles every 200 hours... One is not in tune with the other.
  6. I don't know if I'm wrong, but I see that the correct modern way to progress would be the one that consists of monitoring an engine to finally notice the damage too late. And this may raise eyebrows among some old-school technicians, connoisseurs of the different aspects of preventive and predictive maintenance, who find it a bit daring to trust a method of predicting problems once they have occurred. Especially since, faced with the modern epic of monitoring, there is an ancient history of preventive and curative maintenance, based on the hourly and calendar expertise of the mechanisms for checking the reference states (clearances, pressures, temperatures, regimes), that is to say the above when there are deviations, the degradation of performance. While monitoring notes a performance degradation when it occurs... And you are working on it to deduce the causes. In mechanics, this is called "working backwards", that is to say starting from the effects to treat them, whereas in the old principle of curative maintenance and more advanced preventive maintenance, the effects are avoided by treating the causes in advance, that is to say before the effects occur.
  7. This means that instead of reading nonsense on the internet, I suggest you read SSP 1776 if you have an IO 360 under your engine hood.
  8. As you may have read on the internet, at the risk of taking the information for nonsense, it is not with the internet that the time between the overhaul of an engine and the moment when its useful life ceases is decided... Especially if said engine was born a very long time before the Internet. An engine is a technical object, and only the technique is capable of ruling on its state... Nothing else. And the basis of technical discussions, on the Internet or elsewhere, is the table of limits, that is to say SSP 1776 for an IO 360... Example. If you read this document, on the Internet or elsewhere, you will find that the engine manufacturer does not offer to tell you if the engine is worn out or not depending on the age of the pilot, the year of construction, the flight time, and the country in which you are located. In reality, he just asks you to carry out a metrology of the constituent parts of the engine and to verify that each one respects the manufacturing tolerances, that the engine has a total flight time of 500 or 5000 hours. At certain deadlines, there is a systematic replacement of certain components which is advisable or recommended... And as long as the part is dimensionally and structurally compliant, it is not prescribed to replace it, reuse is quite viable and this is how all engine overhaul workshops around the world work. You can see this every day, especially on the "warbirds" engines whose crankcases and mobile crew are sometimes 80 years old and several times the recommended TBO. I know an IO 360 from 1968 that has more than 4000 hours of flight, it still has its original crankcases, its crankshaft and also the original cylinders # 1 & #3. During its second general overhaul, it is ironed in bore "+ 10" (+ 0,010"), without going under the nitriding layer of the cylinders and received new pistons to the same standard. The solution of replacing an old engine with a new one is not a safer or better solution than that of overhauling. It's just sometimes an economical solution and nothing more. But this takes us away from the subject of monitoring, the benefits of which would be demonstrated if the wear effects observed at each TBO were reduced... Which is still not the case.
  9. Boris VIAN takes up the definition of pataphysics as it appears in Alfred JARRY's "Gestures and opinions of Doctor Faustroll", specifying that "pataphysics is to metaphysics what metaphysics is to physics". Two of the fundamental principles of pataphysics are the equivalence of opposites and the importance given to the exception rather than the general case. Boris VIAN adds that in the scientific field, it is moreover the anomaly that advances the discovery.
  10. Enfin, le meilleur avion composite est celui en métal et bois comme le M20 A...
  11. This tapped hole is present on many cranckcases, it measures 1" deep, made to receive a 1/4 x 3/8" screw. Used for fixing the rear cooling baffle by some, it is not used on Mooney.
  12. A sheet of duralumin, a compas, a ruler, a tracing point, a hand shear and you will have cut 5 or 6 inspection hatches before starting the waterjet cutting machine... I agree that the old hatches are better designed and that the riveted rabbet on the hatch reinforces that... But it is at the expense of the skin of the wing that the screw heads tear.
  13. Mooney also knows that the composite is the future. M 10 T was a good project. Also the skin of the fuselage of M20... And why not a composite wing.
  14. For "EASA", there is a maintenance program (PE), which determines the different operations, they are usually : - VPE 50 hours / 6 months (Visit small interview) ; - VPE 100 hours / 1 year ; - GV 2000 hours / 4 years (big visit). At the hourly or calendar deadline, it is just the type of visit that is mentioned on the booklets (engine, airframe, propeller and road), the description of the work is done on a detailed report that is stapled in the booklets. An "APRS" sheet is in the logbook, it is it that frees the aircraft from maintenance work.
  15. Still a few stations in France, which had to disappear to be replaced by VOR... But the VOR disappeared before ADF... It's good for listening to AM on a night flight...
  16. The subtlety of the "F" wing is a twisted wing at the end, with ailerons that are not. This also posed a concern for roll authority in crosswind on the first "F", hence the change of ailerons in the first series versions (increased travel with new counterweight design).
  17. This leaded fuel constraint is a technical choice, which it is possible to modify easily, just the reduction of the volumetric ratio, if necessary (which will impact the compression ratio) or the control of the cylinder head temperature. Don't tell me Lycoming or Continental can't do... Rotax has chosen a much higher volumetric ratio than Lyco Conti (it is 11), and the engines work with Mogas RON 98 because the temperature of the cylinder head is controlled. So today, the will is that of not doing rather than the technical impossibility of doing. However, I have not seen "GAMI" offer an OH cylinder kit for IO 550 with "liquid" cooled cylinder head and increased compression ratio... It is difficult to create this easily because of the regulations. There is no lambda probe on a 912 S with 100 hp for 1352 cm3 and a compression ratio of 11, working with SP98... No automaton either and it is not necessary at the current stage of the thermodynamics of the Lyco-Conti to resort to automation. The main part of the performance deficiencies of these engines comes from the technical choices of construction which have their interests and their foundations moreover. And the additional automation generates a higher cost on a product that is already too expensive for what it is worth. As you say, indeed, no one buys what is not justified! No, the test cell of "GAMI"is not technically in advance, to convince you of this, visit the workshops "test benches"of a car engine manufacturer, there is enough to make "GAMI" shudder who does not know how to process in ten years what the average car engine manufacturer processes in a day. Knowing that in the automotive industry, where production rates are close to 1 engine per minute, the non-compliance index / non-compliance rate (INC-TNC) is of the order of 4500 PPM, i.e. 4500 defects per 1 million engines produced... This is less than 1 defect for every 200 engines manufactured. I do not believe that the aviation industry is capable of following such a performance indicator for its engine production tool. And indeed, these very modern control facilities are managed by bean counters and not by engineers... Which should appeal. The efforts of "GAMI" are enormous and remarkable, they are to be commended, but after 40 years of activity they are enough to convince of the use of unleaded fuel in a GA... The owner of an "experimental" has been doing this for 15 years... See the gap! Which means that the main part of "GAMI's" efforts is pushing the legs of the FAA elephant lying on its side, so it's not won.
  18. Others also did it before "GAMI" and still do it, for example manufacturers who manufacture between 1500 and 2000 engines per day, for the general public... Engines far more efficient and more complex than a "Lyco-Conti" of 1955 (technology of 1930). The installations of "GAMI" are in all respects comparable to those available to automotive engine manufacturers to test series engines by sampling... You are not unaware that since 1985-1990, in the automotive industry and because of pollution standards, "lean" or "peak EGT" operations has become the operating standard, with an optimization of the power supply and ignition depending on the load and speed, that this is done in real time under the engine cover... In addition, there is added the reprocessing of unburned emissions, which "GAMI" has not yet considered, Lycoming and Continental either, since they do not mention in the engine range the issue of emissions of monoxides - dioxides resulting from an incomplete reduction (the engine is neither more nor less than an energy converter operating by oxidation-reduction). Yes, as you write, "GAMI" sells a dream, that of optimal engine control, comparable to that used on the "liners" of the 50s assuming real-time monitoring of the main parameters... The objective is to save consumption and maintenance. The approach of "GAMI" is honorable and makes sense, I repeat, Except that, unlike the engine or engines of the 50s which were specifically more efficient and almost capable of operating according to these operating standards, our small Lyco-Conti engines are not able to operate in this way due to lack of sufficient thermal stability. If we look at the efforts of this company to try to optimize a single-point injection without pressure control, via the development of calibrated flow rate injectors, it is a fantastic job... For not much. Because you have understood that the simple car on the street now uses a controlled injector operating under high pressure for 15 years, that the control is proactive depending on the load and the speed... And coupling to the ignition diagram... And we could talk about the ignition... Supercharging... Depollution that "GAMI" has not yet addressed. The main obstacle to the "GAMI" is the regulations, they block and freeze all the solutions of technical progress in the name of sacrosanct SECURITY. The engine drive according to the "lean mixture" technique existed long before "Curtiss-Wright" became aware of it, in addition to being carried out on engines much more efficient than those of this firm. In short, the approach of "GAMI" is 80 years behind schedule, it is ancient history since, today, technology allows a spark-ignition engine to operate all the time in "peak EGT" or "lean mixture", in the entire range of speeds and loads... In addition to being optimized in pollution. Take a ROTAX, you no longer have a mixing lever, it is capable of providing more than 100 hp / l of displacement... If your Continental 550 Cu.inch although the 310 hp has been optimized as a Rotax engine, it would be capable of providing 600 hp and would constantly run at peak EGT for lower consumption... And there is no "GAMI" solution in a Rotax, just an engineering from 1985 / 1990.
  19. The "Gami" theories (and others) are not very popularized in Europe. It's not that they are weird or unreal, on the contrary, it's just that it's incomplete and we could say "a bandage on a wooden leg". Here are the reasons : 1) The first reason is that everything is based on an exhaust gas temperature measured elsewhere than in the combustion chamber... Which in no way reflects the quality of the combustion (we can have an excessive temperature and an incomplete reduction). 2) The rule is supposed to preserve an air-cooled engine that does not have the functional capacity to be thermally stable when it is operating at EGT peak, that is to say optimally... It is therefore not an absolute method but a palliative of exploitation according to each use and each engine. I can cite as an example the Rotax or other engines used on various automobiles, they are capable of operating all the time at "peak EGT", for all speeds and load conditions, in addition to being able to develop much higher specific powers (a Rotax 912 makes 74 Hp / liters while IO 550 makes 34.2 Hp / liters at most). And because its engines are viable on this operating condition, it is possible with them to draw trouble or driving statistics. For the other engines, technically unable to allow you to take off at "peak EGT", because the engine will break, so you have to adapt a particular driving and that's where "Gami" makes its butter, and it necessarily has a lot of work. But as you know, the engine manufacturer has already said from the beginning that the CHT are limited... So it's enough to follow the rule, mix so that everything remains within the norm, and that's enough. The day Lycoming and Continental introduce liquid cylinder head cooling with lambda probe combustion control, we will be able to start by seriously discussing driving the engine in "poor" or "rich" mode and possibly with an optimal mixture. In the meantime, keep an eye on your exhaust valves and the cylinder head temperature.
  20. By removing a magneto, you only operate on a candle, which helps to reduce the speed of the flame front... In other words, during a determined engine time, you send more unburned gases into the exhaust, where your EGT probe is located... Where the reduction process continues. This is what makes you notice the increase in EGT. If you increase the engine time (reduction in RPM), you will notice a decrease in EGT... And if you lean in LOP, the reduction will be faster, your EGT will also decrease. Once you have noticed this trend, which is that of all engines with an EGT probe in the exhaust, you will not be able to say that it works well, not well, better or is optimum. Just to be able to say that it works logically and like the previous time.
  21. When we tell you about "electricity fairy"... Well with a Mooney, you believe it !
  22. I like it when the FAA explains to mechanics how they should do their job... But I noticed that the FAA does not like it when someone explains to them that they are not doing their job well. When for the next AD that corrects or cancels the previous one ?
  23. At the top of the page, you can download the plan for cutting according to the original size. This is the canvas that is suitable if your IO 360 A1A has the original oil filter. If the oil filter has been replaced by a cartridge filter base with vernatherm, it is necessary to cut the gummed canvas in a slightly different way and make some small adjustments on the frame. Those details coming soon... See you soon.
  24. The cutout for the side of the aluminum boss of the membrane drain. The gummed canvas should not rub with the aluminum. The slots are located on the steel fittings sides, for dismantling the hood every 100 hours without having to touch the fittings... On steel, the canvas can rub. It is the gummed plate resting on the steel fittings that holds the metal frame at a good distance from the top of the pump. When this canvas sags, there is wear by friction as we have noticed... If the oil filtration screen has remained the original one. If your engine has been modified and it is equipped with a cartridge filter base with vernatherm incorporated, there is another problem... The hexagonal head of the vernatherm pushes on the pump cover, which causes even more failures. If you are a real American, the rivet size is necessarily 3/32"... If you are a bad American anxious to become a good Frenchman, you must use a 2 mm rivet. Do not forget to slip a washer under the head of each rivet...
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